U.S. patent number 4,387,417 [Application Number 06/336,113] was granted by the patent office on 1983-06-07 for lamp retaining means within luminaire.
This patent grant is currently assigned to General Electric Company. Invention is credited to Jerry R. Plemmons, Tommy R. Taylor.
United States Patent |
4,387,417 |
Plemmons , et al. |
June 7, 1983 |
Lamp retaining means within luminaire
Abstract
A retaining means for a lamp within a luminaire provides
structural support and positive positioning. It comprises a
resilient wire formed to a four-sided parallelogram shape with four
outboard reverting projections between segments. One pair of
diametrically opposed projections encircle bolts which hold the
retainer transversely to the lamp axis at the rim of the socket
compartment. Another pair of projections are unrestrained and
provide extra flexibility in accommodating to variations in lamp
diameters.
Inventors: |
Plemmons; Jerry R. (West
Asheville, NC), Taylor; Tommy R. (Fletcher, NC) |
Assignee: |
General Electric Company
(Schenectady, NY)
|
Family
ID: |
23314630 |
Appl.
No.: |
06/336,113 |
Filed: |
December 30, 1981 |
Current U.S.
Class: |
362/376; 362/306;
362/369; 362/390 |
Current CPC
Class: |
F21V
19/007 (20130101) |
Current International
Class: |
F21V
19/00 (20060101); F21V 015/00 () |
Field of
Search: |
;362/306,376,390,369 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Lechert, Jr.; Stephen J.
Attorney, Agent or Firm: Legree; Ernest W. Schlamp; Philip
L. Jacob; Fred
Claims
What we claim as new and desire to secure by Letters Patent of the
United States is:
1. A luminaire comprising an optical assembly having a design light
center,
a single-ended lamp socket,
means for supporting said socket relative to said assembly so as to
locate a lamp accommodated by it in a predetermined attitude
relative to the light center,
and a lamp retainer within said luminaire for positively locating
the lamp in said attitude and securely holding it by engaging its
neck, comprising: resilient wire formed to a four-sided
parallelogram shape with outboard reverting projections between
sides, fixing means engaging one diametrically opposed pair of said
projections for fixing said retainer relative to the optical
assembly, the other pair of said projections being unrestrained and
providing extra flexibility in accommodating different-sized
lamps.
2. A luminaire as in clam 1 wherein the means for supporting said
socket includes a ballast housing having a socket compartment in
which the socket is mounted, the optical assembly being fastened to
the ballast housing at the rim of said socket compartment, and the
fixing means for the lamp retainer being also fastened transversely
to the optical axis at the rim of said socket compartment.
3. A luminaire as in claim 1 wherein said lamp retainer is made of
a single length of spring wire extending from one terminal loop to
a diametrically opposite reverting loop and then back to a second
terminal loop, said two terminal loops superposed on one side and
said reverting loop on the other side forming the diametrically
opposed pair of projections engaged by said fixing means.
4. A luminaire as in claim 3 wherein the outboard projections
formed in said spring wire intermediate each of said terminal loops
and the reverting loop are cusp-like.
Description
The present invention relates to luminaires and particularly to
locating and retaining means for the lamp within a luminaire.
BACKGROUND OF THE INVENTION
High intensity lamps such as mercury, metal halide or high pressure
sodium lamps commonly used in lighting fixtures are usually
single-ended and have a screw base. While the socket into which the
lamp is screwed will locate it and hold it in place, it is
desirable to have some additional means to positively locate the
lamp in the desired attitude or location relative to the
luminaire's design light center. Also in installations subject to
vibration it is desirable to have some additional means to counter
the effects thereof and prevent the lamp for loosening and possibly
fracturing at the socket and falling out. This is particularly
desirable in outdoor luminaires, especially street or highway
lighting fixtures which are subject to roadway vibration and pole
sway caused by wind.
In U.S. Pat. No. 3,694,649--Thompson, Lamp Support Device, a
retaining device for countering the effects of vibration is
described. It takes the form of a pair of elongated stiff wire
members secured to an adjustable lamp socket bracket. These members
extend axially to the neck portion of the lamp and have curved end
portions which engage the neck while encircling it. In addition to
protecting the lamp against vibration-loosening under service
conditions, the support device also facilitates relamping. By
providing support adequate to retain the lamp in the fixture even
after the base is fully disengaged from the socket, the possibility
of the lamp being accidentally dropped by the electrician and
resultant breakage is greatly reduced.
SUMMARY OF THE INVENTION
The object of our invention is to provide an improved retaining
means for a lamp within a luminaire which adapts to variations in
lamp stem diameters, and provides structural support and positive
positioning of the lamp in relation to the reflector together with
ease of lamp replacement. A retaining means is desired which is
cheaper to make than what has been used heretofore and which is
easily installed while the luminaire is being assembled.
In accordance with our invention we provide a resilient wire
retaining means formed to a four-sided parallelogram shape with
four outboard reverting projections between sides or segments.
Conveniently one pair of diametrically opposed projections may be
curved to encircle fixing means such as bolts which hold the
retainer relative to the luminaire's optical assembly. The other
pair are not restrained and provide extra material for flexing in
accommodating to variations in lamp diameter.
In a preferred embodiment, the retaining means is made of a single
length of spring wire extending from one terminal loop to a
diametrically opposite reverting loop, and then back to a second
terminal loop which is juxtaposed to the first on a common axis.
The two juxtaposed terminal loops encircle one retaining bolt and
the reverting loop encircles the other retaining bolt to hold the
retainer in place relative to the optical assembly.
DESCRIPTION OF DRAWING
FIG. 1 is a side elevational view, partly sectioned and with parts
broken away of a luminaire in which the invention is embodied.
FIG. 2 is a plan view of the spring wire retainer.
FIG. 3 is a cross-sectional view through the lamp neck in FIG. 1
showing the retainer in place.
DETAILED DESCRIPTION
Referring now to the drawing and particularly to FIG. 1, there is
shown a luminaire 1 in which the lamp retaining means of the
invention finds particular utility. The luminaire comprises an
optical assembly which includes a dome-shaped housing 2 enclosing
an inner polished reflector 3. The reflector has a configuration
producing a desired distribution of reflected light when a lamp is
properly located relative to the design light center. The reflector
is engaged by the domed housing at the rim 4. The entire optical
assembly depends from and is fastened by bolts 5 or the like to the
rim of a generally cylindrical socket compartment 6 which forms
part of a ballast housing 7. The ballast housing including the
socket compartment may be an aluminum casting. The open end of
domed housing 2 may be closed by a light-transmitting closure or
window 2a in known fashion, for instance as described in U.S. Pat.
No. 3,694,649--Thompson, whose disclosure is incorporated herein by
reference.
A conventional single-ended lamp socket 8 is accommodated within
compartment 6, being fastened to its inner end wall 9. Within the
ballast housing 7 are mounted electrical operating components such
as a ballast transformer (not shown) for operating a discharge lamp
10 shown screwed into socket 8. The illustrated lamp, a 1000 watt
metal halide lamp such as those sold under the registered trademark
Multi-Vapor, is but one example of a high intensity lamp which may
be used in the luminaire.
In accordance with the present invention a lamp retaining means is
constructed and arranged in the luminaire to clamp resiliently
about the neck 10' of the lamp. The retaining means must permit
easy lamp replacement yet provide sufficient restraint to
positively locate the lamp on axis at the design light center and
also retain the lamp when it is unscrewed from the socket. Also it
must accommodate variations in lamp diameter due to manufacturing
tolerances, securely holding smaller diameter lamps but without
fracturing together diameter ones. Referring to FIGS. 2 and 3, this
is accomplished by a flexible wire retainer 11 made of spring wire
formed to a four-sided parallelogram shape with outboard reverting
projections between sides or segments. The retainer is held in
place, transverse to the lamp axis across the mouth or rim of
socket compartment 6 by two of the four bolts which fasten the
optical assembly to the ballast housing at the rim of the socket
compartment. These bolts 5' and 5" engage one opposed pair or set
of reverting projections.
In the preferred construction best seen in FIG. 2 the retainer 11
is made of a single length of resilient wire, suitably 1/16"
diameter steel spring wire. The wire is bent or formed as follows:
beginning with a terminal loop 12, there follows a straight segment
13, then a cusp-like outboard projection 14, a straight segment 15,
a reverting loop 16, a straight segment 17, a cusp-like outboard
projection 18, a straight segment 19 and finally a terminal loop
20. The retainer is preferably sheathed by a cushioning material
capable of withstanding the lamp's operating temperature, suitably
glass cloth sleeving 21 as shown in FIG. 3, to prevent
metal-to-glass contact.
When the retainer is installed in the luminaire, the two terminal
loops 12 and 20 are juxtaposed, that is superposed on behind the
other under one of the retaining bolts 5', while the reverting loop
16 is engaged by the other retaining bolt 5". The retaining bolts
5',5" are shouldered so as to clamp the optical assembly tightly
against the rim of socket compartment 6 but leaving the loops of
the retainer 11 free to flex. Our retainer design thus provides for
quick and easy installation in the process of assembling the
luminaire components.
In use, a lamp 10 is inserted into the socket compartment, the
straight segments 13,15 and 17,19 are forced out and bent slightly,
thus exerting pressure against the neck 10' of the lamp. The
cusp-like projections or outboard ribs 14 and 18 tend to close in
flexing while the reverting loop 16 tends to open. The terminal
loops 12 and 20 have an action similar to that of the reverting
loop 16. The arrangement according to the invention thus assures
adequate flexibility to accommodate expected variations in lamp
neck diameter without fracturing the lamp, while exerting
sufficient pressure on the lamp neck to hold the lamp securely in
place.
The particular embodiment which has been illustrated and described
in detail will accommodate 1000 and 1500 watt metal halide lamps,
1000 and 1500 watt mercury lamps, and 1000 watt high pressure
sodium lamps. Such lamps have a nominal neck diameter of 2.250"
with a permissible manufacturing tolerance of +0.250" and -0.062".
Of course such embodiment is intended only as an illustrative
example and the appended claims are intended to cover modifications
that those skilled in the art may make without departing from the
spirit and scope of the invention.
* * * * *